Device for opening a skylight

ABSTRACT

A device for opening a skylight, particularly for opening same automatically in case of fire. Use is made of a lever attached to the skylight casing and the leverage of which is so designed as to compensate the changing force of an operating spring.

[ 1 3,73%590 r451 ay 29,1973

ilnited States Patent 1 Bogaert 49/386 X .....49/386 X /1966 Shapiro X 1,975,701 /1934 2,565,202 8 1951 Ch t' Pierre Emmanuel Bogaert, Wem- 3 251 158 I m m Em d OB a mm n mm m mm mm [73] Assignee Vic Chemicals Inc FOREIGN PATENTS OR APPLICATIONS ....49/386 ......l6/80 Great 1 6/80 France n .1 a u r. B t a e r G 57 605 999 111 0 7 11 264 935 4 6 1 l 7 9 1 1h 7 1 8 r 2, 3 m 2 l 0 N m m. an D. F A 2 1 2 2 1 .1

Primary ExaminerDennis L. Taylor 1 1 Foreign Application y Data AttorneySughrue, Rothwell, Mion, Zinn & Macpeak Mar. 12, 1970 ABSTRACT [52'] 1.8. A device for opening a kylight particularly for open- [51] Int. 15/20 ing same automatically in case of fire. Use is made of 1 Field a lever attached to the skylight casing and the leverage 49/8, 1; /192; 16/80 of which is so designed as to compensate the changing force of an operating spring.

7 Claims, 3 Drawing Figures 5 6 References Cited UNITED STATES PATENTS 1,716,394 6/1929 Trammell..........1........1.......49/386X PATENIE mzslm SHEET 1 OF 2 PATENTED MAY 2 9 I975 SHEET 2 UF 2 DEVICE FOR OPENING A SKYLIGHT This invention relates to a device for opening a skylight and mainly to such a device which may be used as automatic opening device in case of tire, in combination then with a fusible retainer for the skylight.

Indeed in the present state of the building art, such automatic opening devices in case of fire are used more and more frequently, which brings many problems to the skylight designer.

It is indeed required that such an opening may occur under any conditions, which is the reason why it is necessary to provide strong devices to open the skylight, even when said skylight is covered with a thick snow layer.

Among the problems which are met should notably be mentioned, due to the power of the devices concerned, a requirement for a strong attachment which up to now has only been solved by means of substantial attachment areas.

Another problem lies in maintaining approximately constant from the start the force which is applied to the skylight up to some determined opening. This last requirement in particular has led to the designing of in volved units in which were first to be provided devices generating the opening impulse by the movement bev ginning, said devices then being relieved by opening devices proper.

It is to be stressed that such devices are not only uneconomical but also, due to the elaborateness thereof, they are always more fragile than simple devices and this is the reason why this invention has for object to obviate these drawbacks by providing an extremely simple device which operates consequently absolutely safely, said device allowing to retain a strong enough force, right from the start of the opening movement, said force remaining substantially constant up to some predetermined opening and decreasing thereafter very rapidly.

Moreover said mechanism due to the simplicity thereof, may be fitted to a skylight frame, on very narrow attachment surfaces.

The opening device according to the invention is characterized essentially by being comprised of a lever attached to a pivot point on the skylight frame casing and which is to bear at one end in a guide on the leaf portion, while at the other end said lever is acted upon by a spring attached to the casing upper portion, the lever end on which the spring acts being on the one hand spaced from that axis passing through the lever bearing point on the casing and the pivot point, by such a distance that the leverage thus provided relative to the pivot point be long enough to cause the starting impulse, and on the other hand spaced from the pivot point by such a distance that during the rotating time and right from the opening start, the decreasing force of the spring returning to the rest position thereof be compensated by an increase of the leverage due to the rotating, thus retaining in any intermediate position of the skylight a substantially constant opening force up to some predetermine position.

Other details and features of the invention will stand out from the description given below by way of non limitative example and with reference to the accompanying drawings, in which 2 FIG. 1 is perspective view of a device according to the invention, used as automatic opening device in case of fire. FIG. 1A shows the device of FIG. 1 with the skylight in an open position.

FIG. 2 shown only the lever arranged in such a way as to be adjustable.

In the embodiment shown in FIGS. 1 and la, a skylight frame 1 is comprised of a casing 2, of very narrow shape, and of a leaf or opening portion 3, a lever 4 being attached to the casing 2 in a pivot point 5 and being cranked so as to form an arm 6 which is hinged to the pivot point and bears in a slide 7 on the leaf 3, and an arm 8 which is also hinged to the pivot point 5 of the arm 6 and the end 9 of which is acted upon by a spring 10 which is attached on the other hand to the casing 2, in a point 11 which is located as near as possible to the leaf.

A fusible reatining device 12 is provided to retain the leaf in engagement with the casing by attachment means 13,13 which allow a more or less strong clamping.

By the melting of the retaining device 12, the spring 1 10 acts on the end 9 of the arm 8 and because the lever is sufficiently cranked, with a leverage 14, to generate such a starting impulse that the leaf swings about as shown by arrow 15, eventually coming to rest in the open position shown in FIG. 1A.

During the rotating of the lever 4 about the pivot point 5, the leverage 14 will first increase due to rotating and then decrease, while the spring being less spanned will have a progressively decreasing force. Thus by suitably selecting on the one hand the angle a between the arms 6 and 8 of lever 4 and on the other hand, the length of arm 8, it is possible to obtain a substantially constant force from the startin moment of the opening up to a position which corresponds approximately to five-sixths of the complete opening, said force decreasing thereafter very rapidly. Near the end of the rotational travel of the leaf portion 3 to the open position shown in FIG. 1A the spring 10 acts as a resilient buffer by tending to prevent the leaf portion from rotating past said position. Any continued opening totation or overtravel due to the inertia of the leaf portion tends to raise lever arm 8 above the frame casing 2 and thereby extend or stretch spring 10. This in turn causes the spring to generate a restoring force which halts the overtravel and returns the leaf portion 3 to the position shown in FIG. 1A.

Experience has shown that to obtain an opening of the leaf relative to the casing which corresponds to the skylight width, the preferred dimensions are as follows the pivot point 5 lies at a distance equal to the third of the skylight width from the frame swinging axis, the angle a has an optimum value of and the arm 8 corresponds approximately to 38 percent of the total length of lever 4.

Said dimensions may of course vary but it is to be noted that angle a should remain between a value of to obtain a large enough starting force, and 115, said last limitation being fixed to insure a suitable opening of the skylight.

In the embodiment shown in FIG. 2, the slanting of arm 8 relative to arm 6 of lever 4, is made adjustable for instance by means of a gusset I6 integral with the arm 6 and to which is attached the arm 8; moreover, the attachment points 17 of the spring on the arm 8 are also adjustable within limits and thus it is possible to select according to the spring power and the required original force, the position of each said elements. In the same way, a roller 18 may be attached in various locations on the lever arm 6, so as to make the skylight opening adjustable.

It must be understood that the invention is in no way limited to the above embodiments and that many changes may be brought therein without departing from the scope of the invention as defined by the appended claims.

I claim:

l. A mechanism for opening a skylight including a frame casing, a leaf portion hinged thereto, and a guide on the leaf portion, comprising:

a. a crank lever pivotally attached to a point on the frame casing and having a first end bearing in the leaf portion guide,

b. a spring having one end attached to the frame casing in proximity to the first end of the lever in the skylight closed condition and the other end attached to a second end of the lever,

c. the spring being extended in tension in the skylight closed condition, and

d. the angle of the crank lever measured between axes passing through the ends of the lever and the pivot point being between 1 and 155.

2. A mechanism as claimed in claim 1 wherein the guide on the leaf portion is a slide and further comprising a roller engaged in the slide and attached to the first end of the lever.

3. A mechanism as claimed in claim 1, wherein the distances between the pivot point and each end of the lever are such that during the opening of the leaf portion of the skylight the decreasing force of the spring as it returns to its rest condition is compensated for by an increase of the lever arm of the crank lever as it rotates, thus providing a substan-tially constant opening force up to an intermediate position of the skylight, after which the opening force decreases.

4. A mechanism as claimed in claim 3 wherein the spring acts as a buffer during the final opening rotation of the leaf portion.

5. A mechanism as claimed in claim 4 wherein the angle between the crank lever axes is approximately and the pivot point is located approximately 38 percent, with respect to the total length of the crank lever, from the second end of the lever.

6. A mechanism as claimed in claim 1 wherein the lever comprises two arms angularly adjustable one relative to the other, the ends of one arm having a plurality of spring attachment points and the end of the other arm having a plurality of guide bearing points.

7. A mechanism as claimed in claim 1 wherein a) the skylight is retained in closed condition by a fusible device, and b) the distances between the pivot point and each end of the lever are such that the melting of the fusible device causes the immediate opening of the leaf portion with a substantially constant force up to approximately five-sixth of the rotational travel of the leaf portion, said force decreasing thereafter very rapidly to finally become zero when the spring has returned to its rest position, said spring then forming a resilient buffer. 

1. A mechanism for opening a skylight including a frame casing, a leaf portion hiNged thereto, and a guide on the leaf portion, comprising: a. a crank lever pivotally attached to a point on the frame casing and having a first end bearing in the leaf portion guide, b. a spring having one end attached to the frame casing in proximity to the first end of the lever in the skylight closed condition and the other end attached to a second end of the lever, c. the spring being extended in tension in the skylight closed condition, and d. the angle of the crank lever measured between axes passing through the ends of the lever and the pivot point being between 115* and 155*.
 2. A mechanism as claimed in claim 1 wherein the guide on the leaf portion is a slide and further comprising a roller engaged in the slide and attached to the first end of the lever.
 3. A mechanism as claimed in claim 1, wherein the distances between the pivot point and each end of the lever are such that during the opening of the leaf portion of the skylight the decreasing force of the spring as it returns to its rest condition is compensated for by an increase of the lever arm of the crank lever as it rotates, thus providing a substantially constant opening force up to an intermediate position of the skylight, after which the opening force decreases.
 4. A mechanism as claimed in claim 3 wherein the spring acts as a buffer during the final opening rotation of the leaf portion.
 5. A mechanism as claimed in claim 4 wherein the angle between the crank lever axes is approximately 135*, and the pivot point is located approximately 38 percent, with respect to the total length of the crank lever, from the second end of the lever.
 6. A mechanism as claimed in claim 1 wherein the lever comprises two arms angularly adjustable one relative to the other, the ends of one arm having a plurality of spring attachment points and the end of the other arm having a plurality of guide bearing points.
 7. A mechanism as claimed in claim 1 wherein a) the skylight is retained in closed condition by a fusible device, and b) the distances between the pivot point and each end of the lever are such that the melting of the fusible device causes the immediate opening of the leaf portion with a substantially constant force up to approximately five-sixths of the rotational travel of the leaf portion, said force decreasing thereafter very rapidly to finally become zero when the spring has returned to its rest position, said spring then forming a resilient buffer. 